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Tuesday, 27 March 2012

Stephen Hawking - English scientist, physicist, and mathematician

Stephen Hawking

8 January 1942

English scientist, physicist, and mathematicianDisability: Motor Neuron disease or a variant of ALS (Amyotrophic Lateral Sclerosis)

"Stephen William Hawking is a British theoretical physicist, whose world-renowned scientific career spans over 40 years. His books and public appearances have made him an academic celebrity and he is an Honorary Fellow of the Royal Society of Arts, a lifetime member of the Pontifical Academy of Sciences, and in 2009 was awarded the Presidential Medal of Freedom, the highest civilian award in the United States. Stephen Hawking is severely disabled by motor neuron disease, likely a variant of the disease known as amyotrophic lateral sclerosis (or ALS). Symptoms of the disorder first appeared while he was enrolled at Cambridge; he lost his balance and fell down a flight of stairs, hitting his head. Worried that he would lose his genius, he took the Mensa test to verify that his intellectual abilities were intact. The diagnosis of motor neuron disease came when Hawking was 21, shortly before his first marriage, and doctors said he would not survive more than two or three years. Hawking gradually lost the use of his arms, legs, and voice, and as of 2009 was almost completely paralyzed."

Early life

Stephen William Hawking was born on January 8, 1942, in Oxford, England. His father, a well-known researcher in tropical medicine, urged his son to seek a career in medicine, but Stephen found biology and medicine were not exact enough. Therefore, he turned to the study of mathematics and physics.
Hawking was not an outstanding student at St. Alban's School, nor later at Oxford University, which he entered in 1959. He was a social young man who did little schoolwork because he was able to grasp the essentials of a mathematics or physics problem quickly. At home he reports, "I would take things apart to see how they worked, but they didn't often go back together." His early school years were marked by unhappiness at school, with his peers and on the playing field. While at Oxford he became increasingly interested in physics (study of matter and energy), eventually graduating with a first class honors in physics (1962). He immediately began postgraduate studies at Cambridge University.

Graduate school

The onset of Hawking's graduate education at Cambridge marked a turning point in his life. It was then that he embarked upon the formal study of cosmology, which focused his study. And it was then that he was first stricken with Lou Gehrig's disease, a weakening disease of the nervous and muscular system that eventually led to his total confinement in a wheelchair. At Cambridge his talents were recognized, and he was encouraged to carry on his studies despite his growing physical disabilities. His marriage in 1965 was an important step in his emotional life. Marriage gave him, he recalled, the determination to live and make professional progress in the world of science. Hawking received his doctorate degree in 1966. He then began his lifelong research and teaching association with Cambridge University.

Theory of singularity

Hawking made his first major contribution to science with his idea of singularity, a work that grew out of his collaboration (working relationship) with Roger Penrose. A singularity is a place in either space or time at which some quantity becomes infinite (without an end). Such a place is found in a black hole, the final stage of a collapsed star, where the gravitational field has infinite strength. Penrose proved that a singularity could exist in the space-time of a real universe.
Drawing upon the work of both Penrose and Albert Einstein (1879–1955), Hawking demonstrated that our universe had its origins in a singularity. In the beginning all of the matter in the universe was concentrated in a single point, making a very small but tremendously dense body. Ten to twenty billion years ago that body exploded in a big bang that initiated time and the universe. Hawking was able to produce current astrophysical (having to do with the study of stars and the events that occur around them) research to support the big bang theory of the origin of the universe and oppose the competing steady-state theory.
Hawking's research led him to study the characteristics of the best-known singularity: the black hole. A black hole's edges, called the event horizon, can be detected. Hawking proved that the surface area (measurement of the surface) of the event horizon could only increase, not decrease, and that when two black holes merged the surface area of the new hole was larger than the sum of the two original.
Hawking's continuing examination of the nature of black holes led to two important discoveries. The first, that black holes can give off heat, opposed the claim that nothing could escape from a black hole. The second concerned the size of black holes. As originally conceived, black holes were immense in size because they were the end result of the collapse of gigantic stars. Hawking suggested the existence of millions of mini-black holes formed by the force of the original big bang explosion.

Stephen Hawking.

Unified field theory

In the 1980s Hawking answered one of Einstein's unanswered theories, the famous unified field theory. A complete unified theory includes the four main interactions known to modern physics. The unified theory explains the conditions that were present at the beginning of the universe as well as the features of the physical laws of nature. When humans develop the unified field theory, said Hawking, they will "know the mind of God."

Publications

As Hawking's physical condition grew worse his intellectual achievements increased. He wrote down his ideas in A Brief History of Time: From the Big Bang to Black Holes. It sold over a million copies and was listed as the best-selling nonfiction book for over a year.
In 1993 Hawking wrote Black Holes and Baby Universes and Other Essays, which, in addition to his scientific thoughts, contains chapters about Hawking's personal life. He coauthored a book in 1996 with Sir Roger Penrose titled The Nature of Space and Time. Issues discussed in this book include whether the universe has boundaries and if it will continue to expand forever. Hawking says yes to the first question and no to the second, while Penrose argues the opposite. Hawking joined Penrose again the following year in the creation of another book, The Large, the Small, and the Human Mind (1997). In 2002 he was likewise celebrating the publication of The Universe in a Nutshell. Despite decreasing health, Hawking traveled on the traditional book release circuit. People with disabilities look to him as a hero.

Honors and commitments

Hawking's work in modern cosmology and in theoretical astronomy and physics is widely recognized. He became a fellow of the Royal Society of London in 1974 and five years later was named to a professorial chair at Cambridge University that was once held by Sir Isaac Newton (1642–1727). Beyond these honors he has earned a host of honorary degrees, awards, prizes, and lectureships from the major universities and scientific societies of Europe and America. By the end of the twentieth century Stephen Hawking had become one of the best-known scientists in the world. His popularity includes endorsing a wireless Internet connection and speaking to wheelchair-bound youth. He also had a special appearance on the television series Star Trek.
Though very private, it is generally known that Stephen's first marriage ended in 1991. He has three children from that marriage.
When asked about his objectives, Hawking told Zygon in a 1995 interview, "My goal is a complete understanding of the universe, why it is as it is and why it exists at all."